The present invention relates to a sandwich-type, stampable, metallic structure, to its manufacturing process and to an installation for carrying out said process.
Sandwich-type metallic structures are already known which have the property of being very rigid whilst of low density. Such structures generally result from the assembly of two plate elements, which are relatively thin and flat with a core piece which is thicker, interposed between the two plate elements.
U.S. Pat. No. 3,764,277 describes such a sandwich-type metallic structure, in which the core element, which is constituted of a metallic grid or netting, is sandwiched between two relatively thin sheets of plates, and welded thereto. Although such a sandwich structure has the advantage of being very rigid as well as having a low density, there is nevertheless a disadvantage which is that they are not usable for stamping operation due to the rigid bond produced between the core element and the sheets constituting the two plates as a result of the large number of welding points used to achieve bonding. Said sandwich structure, in consequence, is unsuitable in all cases where the object is to produce pieces of very different shapes by stamping, as for example, in the motorcar industry.
The same applies to the structure described in British Pat. No. 1,128,633 which is a "honeycombed"-type structure in which the walls of the cells are constituted by sandwich-type metallic structures, the core element of which is a metallic netting. Although the wall has had to be deformed in order to form the honeycomb, the result is a particularly rigid piece which cannot be stamped without the geometric structure being deformed.